Heat exchange assembly



March 12, 1957 D. G. PETERSON 784,947

HEAT EXCHANGE ASSEMBLY Filed Sept. 13, 19.54 2 Shee2;s-SheerI l INVENTORDAVID G. PETERSON ATTORNEY March 12, 1957 Filed Sept. 13, 1954 D. G.PETERSON HEAT EXCHANGE ASSEMBLY 2 Sheets-Sheet 2 FIG. 2

INVENTOR DAVID G PETERSON United States Patent 2,784,947 HEAT EXCHANASSEMLY Applicationseptember 13, 1954, Serial No. 455,696

5 Claims. (Cl. 257-445) The present invention is concerned withimprovements in plate type exchangers utilized for the` transmission ofheat between twQ confined lluids and it relates particularly to animproved method of.Y assembling heat exchanger envelopes having rowsofundulated wires and corrugated channels providing extended` surfacefins.

A well known type of apparatusfor the transfer of heat between twoconfined fluids comprises a plurality of metallic plates spaced` apar-tto form passages through alternate ones of which a relatively hot fluid`such as exhaust gasA flows while air or other fluid to be heatedtraverses the intermediate passages. Commonly a series of envelopecomponents are provided consisting of parallel plates with the spacetherebetween closed along one pair of opposite edges to laterally boundopposite sides of the passage for the heating fluid. The envelopecomponents are mounted in spaced parallel relation to form the passagesfor the fluid to be heated and the interenvelope spaces are similarlyclosed along one pair of opposite side edges. Such spaced envelopes forma core that is usually enclosed within :a housing with which areassociated inlet and outlet manifolds and supply and discharge ducts forthe two fluids.

To increase heat transfer elllciency the walls of the tluid passages arefrequently provided with ns projecting into the path of the fluids andserving to increase the conduction of heat to and through the Walls thatbound Ithe passages. One form for the extended surface iin-S extendingbetween walls comprises sinuously bent wires forming a continuous seriesof `Ushaped loops whose legs constitute pin like fins projecting fromthe walls bounding the passage within the envelope. On the outer face ofthese Walls extended surface may be provided in the form of channelmembers extending parallel to the direction of fluid flow. To promoteefficient heat transfer through pins and passage separating walls goodbonds must be provided between the elements and the wall members such asby brazing or welding.

The present invention is directed to an improved arrangement orassembling the plates that form the passage walls and the sinuouslylooped wires that constitute the extended surface from these walls so asto form an integral heat exchange envelope.

'Ihe invention will be best understood upon consideration of thefollowing detailed description of several illustrative embodimentsthereof when read in conjunction with the accompanying drawings inwhich:

Figure l is a fragmentary perspective view of a heat exchanger envelopecomponent with a wall partially broken away to show double compositechannels utilized to hold the sinuous wire iin elements in position.

Figure 2 is a perspective view illustrating the use of a slightlydifferent positioning and retaining channel from that shown in Figure l.

Plate type heat exchangers of the general type herein disclosed are madeup from a plurality of separate envelope components, each comprisingmetallic plates 11 and 12 2,784,947 Patented Mar. 12 1957 spaced apartto form a passageway 13 for one fluid' while spaces outside the walls 11and 12 which are located between adjacent envelope components of acompleted heat exchanger llorm passages for the other fluid, To provideextended surface in the passageway 13 a plurality of fin elements aremounted between the inner surfaces of the walls 11 and 12 in the form ofwires 14 sinuously bent to form U-shaped loops extending back and forthso the leg portions thereot` constitute pin like fins 15 extendingbetween the walls. To facilitate bonding these sinuous elements to thepassage walls 11` `and 12, channel members 16 are fitted over and alongadjacent yoke portions of the sinuously bent elements. These samechannel members also serve as stiffeners which increase the loverallstrength and rigidity of the assembled envelope thereby greatlyenhancing its final utility.

. In bonding the passage wall plates` 11 and 12 together with thesinuous wire members 14 .and the channel' members 16 into an integralunit, a process of furnace brazing has proved most satisfactory, sinceby such a process the constituent elements yare placed in a mutuallygood heat transfer relationship and the entire `operation may bespeedily performed with a minimum 4of handling. The devices of thisinvention incorporate the use of permanent wire positioning channelswhichposition the sinuous Wire elements andv provide stability to. theconstituent elements during the brazing operation.

Figure l illustrates a type of heat exchanger envelope componentcomprising `a pair `of plates 11 and 12 separated by parallel rows ofsinuously bent wires 1 4 forming a continuous series of U-shlaped loopswhose legs comprise pins 15 extending from plate 11 to plate 12. In thisarrangement, a series of composite channel members 16 -are used toposition -the loops of eac-h wire element adjacent the top and bottomplates. The channel members 16 are rolled as a single unit with onechannel portion 16A adapted to hold the sinuous wires in an uprightposition while the adjacent channel 16B serves as a spacer maintainingadjacent sinuous wires 14 evenly spaced.

In assembling this unit in preparation for the brazing operation, theplate 12 is first supported .in a horizontal plane .and a sheet orquantity of brazing material 17 is placed thereupon before rows of thecomposite channel members 16 are stationed in juxtaposition along theplate with the open or channel sid-e thereof facing upward. The loops oryokes of sinuously bent wires are press fitted into the alternatechannels 16A while the intermediate channels 16B are left unoccupied.and provide a positive spacing means abutting the next channel 16.Similar channels 16, brazing material 17 and an upper plate 11 aresuperposed over the upper wire loops to provide the assembly of Figurel. Additional brazing material is used as a liner 1S within each channelpart 16A containing the wire loops, so that when the entire assembly isheated to a brazing temperature all the brazing material will melt andon cooling will solidify to bond the Wire loops to the channels and thechannels to the plates defining the passage walls with an adequatequantity of brazing material at the exact point of usage.

Figure 2 illustrates a variation of the heat exchanger component shownin Figure 1, differing only in the specific form of the wire holdingchannel. In the device of Figure 2 the wire positioning and retainingchannels 20 and 24 are spaced vapart by a web 22 while a spacer flange26 adjoi'ns channel 24 to provide a positive spacing means to the nextadjacent double channel member. Ihe web 22 and the flange 26 producewhat is, in effect, base portions of inverted channels alternatelyplaced and in a juxtaposed relation with the upright channels 20 and 24.

In assembly, brazing material is inserted between all rice surfaces tobe joined such 4as between the channels and plates, and `also within thechannels so when the oomposite unit is raised to a brazing temperature,a plentiful supply of molten brazing material Will be available at theapproximate location of its ultimate use.

What l claim is:

1. An envelope for a heat exchanger comprising metallic plates spacedapart to form walls for a iluid passageway; `a plurality of heatexchange elements mounted i'n spaced parallel relation in saidpassageway as metallic wires sinuously bent to provide a plurality ofU-shaped loops with leg portions extending in an upright relationbetween the plates .and intervening loop` portions lying adjacent `saidpassage walls; and means positioning each sinuous wire relative toadjacent sinuous wires, said means including channel members bridgingadjacent loops of each sinuous wire together with metallic spacerspositioned uniformly at one side thereof to extend transversely adistance substantially equal to the width of one of said channelmembers.

2. An envelope for a heat exchanger as dened in claim 1 wherein themetallic spacer comprises a channel member integral with and similarlydisposed to the first namedchannel member.

3. An envelope for a heat exchanger 'as denedin claim 1 whereinalternate spacers comprise web portions of channel members having sidesin common with adjacent wire positioning channels.

4. An envelope for a heat exchanger as defined in claim l wherein `theweb portion of the metallic spacers lie substantially parallel to andremoved from each passage wall.

5. An envelope for a heat exchanger comprising metallic plates spacedapart to form walls for a fluid passageway therebetween; a plurality ofheat exchange elements mounted in spaced parallel relation in saidpassageway comprising metallic wires sinuously bent to provide a seriesof longitudinally aligned loops whose leg portions extend in an uprightrelation between plates and whose intervening yoke portions lie adjacentsaid passage walls; channel elements bridging aligned yokes 'alongopposite' sides `of the sinuous wires to impart longitudinal stabilitythereto; and a metallic spacer channel between adjacent channel elementsintegral with at least one of said channel elements arranged to impartlateral stability thereto, the transverse dimension of said metallicspacer channel being similar to that of said channel elements to providea positive spacing means with a minimum resistance to fluid ow.

' References Cited in the file 0f this patent UNITED STATES PATENTSBlackmore July 9, 1918 2,151,206 Hawthorn Mar. 2l, 1939 2,550,512Woolrich Apr. 24, 1951 2,591,878 Rogers et al. Apr. 8, 1952 2,606,007Simpelaar Aug. 5, 1952 2,614,517 Peterson Oct. 21, 1952 2,697,588 JensenDec. 21, 1954

